/*
   =============================================================================
	showcg.c -- show the contents of a VSDD character generator table
	Version 10 -- 1988-01-26 -- D.N. Lynx Crowe
   =============================================================================
*/

#include "stdio.h"
#include "stddefs.h"

#define	NPIXELS	8

#define	NCHARS	0xE0

#include "cg2.c"

int	bitmask[] = {

	0x0001, 0x0002, 0x0004, 0x0008,
	0x0010, 0x0020, 0x0040, 0x0080,
	0x0100, 0x0200, 0x0400, 0x0800,
	0x1000, 0x2000, 0x4000, 0x8000
};

/*  */

/*
   =============================================================================
	bitrev(bitsin, nbits) -- reverse the rightmost nbits of bitsin.

	Any bits to the left of the reversed bits in the result will be zeros.
   =============================================================================
*/

int
bitrev(bitsin, nbits)
register int bitsin, nbits;
{
	register int	n, m;

	n = 0;

	for (m = 0; m < nbits; m++)
		if (bitsin & bitmask[m])
			n |= bitmask[nbits-1-m];

	return(n);
}

/*  */

/*
   =============================================================================
	pbits(row, bits) -- print the bits in a row of a character
   =============================================================================
*/

pbits(row, bits)
register int row, bits;
{
	register int	j, k;

	k = bits;

	for (j = 0; j < NPIXELS; j++) {

		if (bits & 1)
			putchar('*');
		else
			putchar(' ');

		bits = bits >> 1;
	}

	bits = bitrev(k, NPIXELS);

	printf(" %1x %02x  ", row, bits);
}
			
/*  */

main()
{
	register int	ch, irow, ich;

	for (ch = 0; ch < NCHARS; ch += 4) {

		printf("\n\n\t");

		for (ich = 0; ich < 4; ich++)
			printf("Ch %03d/%02x/%03o  ", ch+ich, ch+ich, ch+ich);

		printf("\n\t");

		for (ich = 0; ich < 4; ich++)
			printf("76543210   DA  ");

		printf("\n");

		for (irow = cg_rows - 1; irow GE 0; irow--) {

			printf("\t");
			pbits(irow, cgtable[irow][ch]);
			pbits(irow, cgtable[irow][ch+1]);
			pbits(irow, cgtable[irow][ch+2]);
			pbits(irow, cgtable[irow][ch+3]);
			printf("\n");
		}

		if ((ch & 0x0F) EQ 12)
			printf("\f");
	}
}